I. Field of the Invention
The present invention relates generally to the field of ballistics, and more particularly to a method and apparatus for trapping bullets for ballistics testing.
II. Description of the Related Art
In many areas of law enforcement, ballistics and forensics, projectiles such as bullets are recovered from crime scenes and compared to a projectile fired from a gun that has been determined to have been used in a crime. Each barrel of a gun has a unique xe2x80x9cfingerprintxe2x80x9d. This fingerprint is in the form of unique striations, typically called lands and grooves. A land is a raised area on internal part of a gun barrel. A groove is typically located between lands. A barrel land typically leaves a corresponding groove on a bullet fired from that barrel. A barrel groove typically leaves a corresponding land on the bullet fired from the barrel. It is often necessary to use projectile research apparatuses such as tanks of water and tanks of ballistics gelatin into which projectiles are fired for research. The goal is to recover the projectile in as near perfect condition to carry out the studies, to determine whether the bullet recovered from the crime scene matches the bullet from the gun determined to have been used in the crime. However, often times the projectile is damaged from the testing medium itself rendering the tests with inaccuracies. One problem is that the testing medium, for example, the water or the ballistics gelatin, is nearly incompressible. Therefore, when the projectile is shot into the medium, although the medium provides a path for the projectile, the projectile can be damaged from the medium due to the incompressibility of the medium. For example, a hollow tip bullet can often xe2x80x9cmushroomxe2x80x9d, greatly distorting the lands and grooves from the barrel. A researcher often must fold the mushroomed portion of the bullet to interpret the marks. Furthermore, the bullet fired into the test medium can shatter, and the pieces must be recovered for testing and interpretation.
Therefore, markings left on the projectile, that is, the lands and grooved, from the barrel of the gun from which the projectile was shot are also deformed, flattened or otherwise distorted making it difficult to analyze the projectile and compare it with the crime scene projectile.
In accordance with the present invention and the contemplated problems which have and continue to exist in this field, the invention features a method and apparatus for recovering a projectile with minimal to no damage to the projectile, making subsequent testing and interpretation easier for the researcher. Often times, the bullet fired into the recovery apparatus is in pristine condition.
In general, the invention provides systems and methods that allow a projectile of interest to be fired into a projectile-capturing medium. The preservation of the bullet in a condition as close as possible to the condition of the bullet as it exits from the gun, with little to no damage from the projectile-capturing medium is the primary goal of the methods and systems. The medium is adapted to protect, preserve and secure the projectile for subsequent recovery and testing. The medium typically does not cause any damage to the projectile as with prior art systems. Sometimes, the medium can cause damage to the projectile, but it is typically minimal as compared to the prior art. The medium is typically comprised of alternating layers of a fibrous material and a foam material.
In operation, a projectile collects several fibers from the fibrous material as it travels though the fibrous layers. In typical embodiments, the fibrous material is natural cotton. Natural cotton includes features that maximize projectile capture but that do not damage the projectile. One feature of the cotton is the ability to release individual fibers to the projectile as the projectile passes through the fibrous layers. This collection of fibers on the projectile is a simple mechanical collection and the fibers can subsequently be manually removed with relative ease. Therefore, the natural cotton tends not to stick to projectile, not to burn from the heat of the projectile, or deform the projectile. If the fibers stuck to the projectile or other wised fused to the projectile, for example, from burning, the projectile would not be preserved for study and testing. While the fibers collect on the projectile, they provide enough friction to collect additional fibers on the fibers that have already collected on the projectile thereby causing a cotton xe2x80x9cballxe2x80x9d to form around the projectile. It is this ball that protects the projectile from most damage in subsequent projectile-capturing medium layers. Therefore, the first layer in the alternating layers of cotton and foam is typically a cotton layer. Therefore, when the projectile covered in cotton fibers enters the next layer, a foam layer, the impact of the projectile covered in cotton fibers with the foam layer does not cause damage to the projectile. The projectile covered in cotton can then pass through subsequent layers of cotton, gather more fibers and pass through subsequent layers of foam which further decreases the velocity, momentum and kinetic energy of the projectile.
In general, in one aspect, the invention features a projectile recovery apparatus, including an elongated trough having a first end, a second end, a longitudinal axis and a substantially hollow interior, a projectile-capturing medium positioned in the entire interior of the trough and oriented about the longitudinal axis, and wherein one of the first and second ends is open, exposing the interior filled with the medium, and the other end is closed.
In one implementation, a first portion of the medium is a fibrous substance adapted to cover and protect the projectile and a second portion of the medium is a foam substance that is adapted to decrease the velocity of the projectile covered with the first portion, the first portion protecting the projectile from contact with the second portion.
In another implementation, the fibrous substance is natural cotton including fibers that are adapted to gather around the projectile to cover the projectile.
In another implementation, the fibrous substance and the foam substance are arranged in alternating layers.
In another implementation, the closed end is adapted to be removed to expose the interior of the trough, whereby a second elongated trough having additional projectile-capturing medium can be connected to the elongated trough to lengthen the apparatus.
In another implementation, the medium is a foam substance.
In another implementation, the foam substance is polyurethane.
In another implementation, the medium is a fibrous substance.
In another implementation, the fibrous substance is natural cotton having individual fibers that can be released to gather on the projectile.
In another implementation, the apparatus includes a series of openable hatches that can expose the filling material at various locations along the longitudinal axis.
In another aspect, the invention features a projectile recovery apparatus, including an elongated trough having an open end, a closed end, a longitudinal axis and a substantially hollow interior, a fibrous layer located at the open end and adapted to cover a projectile fired into the apparatus with individual fibers from the fibrous layer at least one foam layer located between the fibrous layer and the closed end and adapted to decrease the velocity of the projectile covered in the fibers from the fibrous layer that protects the projectile from contact with the foam layer, wherein the fibrous layer and the foam layer are configured along and about the longitudinal axis, and filling the interior.
In one implementation, the closed end be removed to expose the interior of the trough.
In another implementation, the apparatus includes a series of openable hatches that can expose the filling material at various locations along the longitudinal axis.
In another implementation, the apparatus includes at least one additional foam layer adapted to further decrease the velocity of the projectile and at least one additional fibrous layer having individual fibers that are adapted to further cover the projectile, wherein the foam layers and fibrous layers are alternately configured along the longitudinal axis.
In another implementation, the foam layers and the fibrous layers are substantially perpendicular to the longitudinal axis and substantially parallel with respect to each other and wherein each layer is in contact with the nearest layer.
In another implementation, the foam layers and the fibrous layers are positioned about the longitudinal axis at an orientation other than perpendicular to the longitudinal axis and substantially parallel with respect to each other.
In another implementation, the foam substance is polyurethane.
In another implementation, the fibrous substance is natural cotton.
In another aspect, the invention features a method of recovering a projectile, including providing a projectile recovery system, including an elongated trough having an open end, a closed end, a longitudinal axis and a substantially hollow interior and a projectile capturing medium positioned in the entire interior of the trough and oriented about the longitudinal axis, wherein a fibrous portion of the medium is adapted to cover and protect the projectile and a foam portion of the medium is adapted to decrease the velocity of the projectile covered with fibers from the fibrous portion, the fibrous material protecting the projectile from contact with the foam portion, shooting a projectile into the projectile recovery system substantially parallel to the longitudinal axis, wherein the projectile is aimed at the medium, the medium being alternately oriented in layers, wherein the first layer of the medium is a fibrous layer, wherein the projectile passes through the fibrous layer gathering fibers around the projectile, then into a subsequent foam layer, decreasing the projectile velocity, then into subsequent fibrous and foam layers, gathering more fibers from the fibrous layers and further decreasing the velocity through the foam layers until the projectile has stopped, searching through the medium of the projectile recovery system for the a fibrous ball that contains the projectile, and recovering the projectile from the fibrous ball.
In one implementation, the medium is a foam substance.
In another implementation, the medium is a fibrous substance.
In another implementation, the medium comprises alternating layers of fibrous material and foam material.
In another implementation, the method includes performing ballistics tests on the projectile.
In still another aspect, the invention features projectile recovery apparatus, including alternating layers of cotton and foam oriented about a longitudinal axis, the alternating layers of cotton and foam having an overall distance for a projectile to come to a full stop when the projectile is fired into the layers along the longitudinal axis.
In yet another aspect, the invention features a projectile recovery system, including an elongated trough adapted to receive a projectile, means for covering the projectile with a fibrous material and protecting the projectile, the means located within the trough and means for decreasing the velocity of the projectile, the means for covering the projectile protecting the projectile from the means for decreasing the velocity of the projectile, the means for decreasing the velocity of the projectile located within the trough.
One advantage of the apparatus is that a projectile to be studied can be shot into the projectile-capturing medium of the system and can be recovered with minimal to no damage to the projectile for ballistics and forensics research.
Another advantage is that the projectile-capturing medium minimally damages the projectile itself.
Another advantage is that the projectile retains markings, striations, lands and grooved representative of being shot from a unique barrel.